Preserve output formatting with spin --show-output

[h0adp0re]

Is your feature request related to a problem? Please describe.
It looks like gum spin --show-output strips stdout of all escape codes.

Describe the solution you'd like
It'd be great if output would be 1:1 as if run without gum spin; colors, newlines, the works.

[caarlos0]

hey!

that's likely the program being run detecting stdout is not a terminal and then not printing any colors

most CLIs have an option to force colors, such as --color=always on ls, or setting env vars like CLICOLOR_FORCE=1.

we could maybe run the program on tty, though, @aymanbagabas what do you think?

[aymanbagabas]

We certainly could conditionally run the program on TTY when Stdout is a terminal. Since we only display the output/error after Gum exits, we can just output the recorded output/error from the TTY to os.Stdout/Stderr. In this case though, we probably will need two TTYs for Stdout and Stderr.